Luke tried to feel that mana, and he frowned when he failed. He felt that he would get another clue by doing so. Still, it was the first time he saw mana acting like that after defeating a foe, and it wasn't the first time he killed a monster with so much mana.
You obtained 300.000.000 experience points.
You obtained 150.000.000 gold coins.
You leveled up.
You obtained 1565 status points.
…
Aside from the skills level-ups and its notifications, Luke didn't see anything else, so that thing wasn't an overlord. In any case, all the sand disappeared, and he found a blue crystal a few meters away from where he landed. He probably had to touch that to reach the next floor, but that didn't make sense. He wasn't the first one to come there, so others were supposed to have killed that monster and used the same method to proceed.
"Something feels off, but I can stop here and think about it…" Luke thought.